Scientists in Israel performed a study on bumblebees, discovering that they appear to give up sleep in order to care for the larvae and even the pupae that don’t require feeding.
All animals need to sleep. It’s obvious for us as humans how necessary it is to function well, but we aren’t the only ones who need it, not just for performing daily tasks, but also for health and survival.
However, there are certain times where skipping sleep is best because it gives more time for migration, gathering food, or staying safe from predators.
Human mothers, for instance, could tell you that they naturally sleep less and wake up throughout the night when they are near their babies. Rat mothers wake up whenever their pups drink their milk. It seems as if mothers respond to their baby’s behavior.
They do this even if the young are not their own
Scientists were intrigued to find that bumblebees had similar instincts, so to understand it better, they filmed the bees and watched them throughout numerous experiments.
They tried a number of different combinations of male and female pupae and larvae to compare how their sleeping habits changed.
Interestingly, bee pupa, the stage just after larvae, don’t move, make noise, or need to be fed. However, the older bees still give up sleep in order to care for them.
Other factors they found connected to less sleep were round-the-clock activity and wax-pot buildings, both factors you’ll find with mother queens who create nests.
In comparison, the scientists found that the control bees who were not exposed to the pupa and larvae were more active during the day. And when they removed the pupa from the cocoons, the scientists also found that some bees still gave up sleep for a little while yet. It seems that infants may be leaving behind a substance, like a pheromone, for example, which affects bees’ sleep.
When the scientists removed the offspring completely, then the carer bees really slept, but they still slept less than the control bees, suggesting they had become accustomed to less sleep.
It’s still unclear, however, why the young bees needed 24/7 care. One of the suggestions the scientists have made is that it could help speed up growth, enabling the workers to regulate the brood’s temperature.
“Bumblebee sleep is incredibly sensitive to the presence of brood,” the researchers wrote.
Co-author Guy Bloch, professor of biology at The Hebrew University of Jerusalem told Newsweek:
“We spend much of our time asleep, but still we do not know what is the biological function of sleep. Given that nursing bees are active around-the-clock, we suspected that this activity pattern also affects their sleep and that the evolution of sociality in which some of the bees spend much of their time caring for the young, maybe shaped the way their sleep is regulated.”
Bloch also noted that the results of the study continue to illustrate the mystery of sleep and how “there is profound plasticity” in the behavior of some animals. He is looking forward to what future research will show.
“We do not know if the brood tending bees pay a cost for reducing the amount of sleep,” he said. “Alternatively, it is possible that bees evolved mechanisms allowing them to perform well with less sleep.”